Quote, "During the summeer, some lakes and swamps dried up, so some fish developed a primitive lung to breathe air until the rains came." Those must have been some special fish, because every fish I have seen dies in a few minutes without water. I know...they died and then came back to life once the rains came. Over millions of years, they bacame very tired of dying and coming back to life, so it just made sense to develope a lung... and maybe reverse scuba gear for that pesky transistional period.